J A Bello
Abstract: This study highlights the use of plastered straw bale as a load bearing wall, its method of construction and specification required to obtain optimum benefits of this element. Critical Path Analysis (CPA) was used in formulating, scheduling and managing the various milestones or activities in the construction of a plastered straw bale walled building. CPA arising from this work provides an empirically constructed schedule of planning activities for straw bale wall and other auxiliary building elements (foundations, roof, lintel and brick columns) to meet some self-imposed or institutionally required calendar of events. The critical path analysis was developed using Microsoft Visual Basic 6 Software to determine the critical path in the construction schedule. The construction basic data are input into the activity interface which comprises the activity name, description, predecessor activity, start node and end node. The economic analysis of the construction work has shown that the total actual cost of the residential building is 0.77 of the same building built with sandcrete wall with scheduled times of 29.64 and 28.64 weeks respectively.
Keywords: Automation, construction, straw bale, plaster, critical path analysis___________________________________________________________________________
Introducing the Use of Evolutionary Programming by Applying Chaos Theory, pp 15-24
B MarszomAbstract: A single cell would struggle hard, among a pool of cells, to survive, while another cell would also struggle harder and another very hard, but who ever is fit among the population of cells would survive. Survival in this sense does not mean that the harder the fitness, rather the survival is fit by random selection or chaos and not by order. The random chance of variation together with the law of selection is a problem-solving method of immerse power.This work introduces the use of this principle to optimize design of engineering problems and give manual computations to some examples and generic idea of computer programming.
Keywords: Chaos theorem, genetic algorithms, genetic programming, evolutionary programmingFullText ___________________________________________________________________________
Evaluating Thermal Resistivity of Cement Plastered Straw Bale Wall: A Review, pp 25-31
K P Malcom, S Yiching and R T Gwundu
Abstract: In this work, cement plastered straw bale specimens of sorghum and maize straw bale were tested for thermal conductivity using Lee’s Disc apparatus. Thermal resistivity of the plastered straw bale specimens were evaluated as the reciprocal of the apparent thermal conductivity. The results of the experimental tests and calculations have shown that increase in the thickness of the plastered Straw bale masonry would increase their thermal resistivity. Though, this effect varies slightly from sorghum to maize of the straw bale masonry. This occurred at the masonry thickness of 400 mm. The thermal resistivity of wood specimens (6 mK/W at the masonry thickness of 350 mm) measured with the same apparatus agreed to within 1.21 of the published values for sorghum and maize at the thickness of 400 mm..
Keyword: Thermal resistivity, thermal conductivity, thermal resistance, sorghum, masonry
Developing an Alternative Guardrail System for Exclusive Motorcycle Lanes, pp. 32-43
A B Ibitoye, A M S Hamouda, R S Radi and S V Wong
Abstract: In most motorcycling countries, especially in Asian and African countries, complex safety problems arise as the roads and infrastructures have not been developed at the same pace as motorcycle ownership and traffic. The tremendous increase in number of motorcycles and fatalities warranted introduction of exclusive motorcycle lanes in Malaysia and installation of existing guardrail along roadside constitute safety risk to motorcyclists. The potential injury risk of existing guardrail on motorcyclists was investigated using three-dimensional computer software application. Motorcycle and guardrail were modelled as Multi-body and Finite elements systems respectively. The obtained results confirmed that the existing w-beam guardrail is not safe to motorcyclist, especially for the head injury at impact speed of 48km/h and impact angle of 45 degree. The study then used design optimization of twenty-four alternative models to propose an alternative guardrail design. The major conclusions of the study are that modification of the configuration and material of the existing guardrail can significantly reduce potential injury risks to motorcyclists and that the proposed alternative guardrail design could be considered safe to replace the existing guardrail along exclusive motorcycle lane.
Keywords Motorcycle, crash collision, alternative guardrail, safety implication, potential injury
An Evaluation of Material Management System Used by Contractors and its Effects on Project Performance, pp 45-52
Tajudeen Olufemi Salami
Keywords: Construction industry, contractor, materials management, procurement, time-delays.
H. D. Olusegun, A. S. Adekunle, O. S. Ogundele, S. and I. O. Ohijeagbon
Promoting Formal Employer-led Carpool Schemes as Perceived by their Users, pp 60-68
Keywords: Soft measures, carpooling, car sharing, incentives, policy.
Vol. 1, No. 2, 2011
Investigating the Effect of Travel Time Variability on Drivers’ Route Choice Decisions in Ilorin, Nigeria, pp 69 - 76
I. T. Yusuf
Keywords: Travel time variability, travel time uncertainty, binary probit model, stated preference survey
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Belt Usage Compliance among Drivers in Ilorin, Nigeria, pp 77- 82
A. B. Ibitoye and A. M. Naallah
Keywords: Seat belt, commercial drivers, compliance, accident, influencing factors
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Estimation of Aerosol in Building Design in Tropical Sub-Region, pp 83-88
C. Fagnou and A. L. Amoah
K eywords Internal microclimate, aerosol, design, humid, sub tropical region
Cost Optimization of Sandcrete Blocks through Partial Replacement of Sand with Lateritic Soil,pp 89-94
O. Joshua and P. O. Lawal
Keywords: Economic block, laterized brick, laterized sandcrete block, lateritic soil
Structural Behaviour of Palm Kernel Shell Concrete at Elevated Temperature, pp 95-101
R. A. Olaoye, S. O. Ajamu and J. R. Oluremi
Keywords: Palm kernel shell, temperature, percentage replacement, compressive strength
A Frame Work for Improving Management of Claims in Construction Projects, pp 102-113
Tajudeen Olufemi Salami
Keywords: Claims, construction professional, disputres, framework management
Abstract: Agricultural residues in their natural form could not be effectively and efficiently utilized. Therefore, this study investigated the effects of processing on the densification characteristics of agricultural residues using processing and briquetting of corncob as a case study. An existing briquetting machine was used to produce briquettes from corncob residue. Corncob residues were subjected to size reduction and a particle size of 0.60 mm representing fine series was chosen for the experimental aspect of this work. The moisture contents of raw, processed and briquetted corncob were determined using ASAE standard methods. Also determined were bulk densities of raw and processed corncob. The initial, maximum and relaxed densities of briquettes produced from the blend of corncob residue and cassava starch gel were also evaluated. The values of some densifications characteristics obtained for raw, processed and briquetted corncob were compared and relevant deductions were made. Bar charts were drawn to compare and contrast the values obtained for raw and processed corncob. The mean moisture content of the raw corncob was 9.64%, while the corresponding value for relaxed briquettes were 7.86%. The values of bulk densities of the raw residue materials and ground (processed) were 50.32kg/m3 and 95.33kg/m3 respectively. The initial, maximum and relaxed densities of uncompressed treated corncob, compressed and relaxed briquettes were respectively 154kg/m3; 760kg/m3 and 449.60kg/m3.The study concluded that subjecting agro-residues to one kind of processing or the other significantly affected its fuel properties and that the high value of relaxed density obtained in this study suggests that corncob briquettes would be stable and could be transported over a long distance with ease without disintegration.
Keywords Agro-residues, corncob, briquetting, processing, density
Vol. 1, No. 3, 2011
Seismic and Flood Retrofitting and Structures Safety by Smart Elements, pp122-129
I. Oppong and L. Barry
Abstract: Architizer (News, 2011) published a great info-graphic about retrofitting existing buildings to withstand the seismic shifts of earthquake-prone areas. They examined two of the more pro-active strategies for preparing older structures—mass dampers isolation: a counter-vibration to an earthquake and a base isolation that basically decouples an above ground building from its below ground foundation. This article reviews the methods and compares the application smart structural materials to the effect that the failure rate is drastically reduced to a safety stage.
Keywords: Damper, flood, retrofitting seismic, structures, smart elements,
Sampling of Intersections for Traffic Delay Study in an African Sub Region Urban City, pp 130-137
O. O. Adeleke and Y. A. Jimoh
Abstract: For an effective city wide management of urban transportation and socio-economic working of the city, within time and fund constraint in a developing sub region, the need for a reliable database with enough coverage of all the intersections in the road network is desirable. This is in view of economy (in terms of insufficient time and manpower) for data gathering on all the intersections where the stake of competing needs of resources is high. The paper presents a cost saving strategy that can be used for effective sampling of representative nodes from the large number that make up the road network of an urban area which reflect the various traffic and urban movement characteristics. The criteria used for the representative sampling of the nodes of the urban network in the city of Ilorin, Nigeria include intersection geometry, number of intersecting legs, road dualisation status (divided/undivided), number of approach lanes, traffic situation (under saturated/saturated), approach slope and environmental factors. Eventual data collection at 8 out of the 37 urban intersections resulted to an 80% reduction in the number of personnel and implied enumeration cost; while still reflecting the physical and urban movement characteristics for the entire network.
Keywords: First priority arterials, intersection types, GPS, cost of enumeration
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Internal Microclimate: Service Life Assessment for a Building attached with a Solar Chimney-Collector, pp138-147
Adeola A. Adedeji, Jacob. O. Aweda and Olumuyiwa A. Lasode
Keywords: Energy, solar collector, chimney, reliability, service life
Erosion Control on Ahmadu Bello Way, Ilorin, Using Storm Drain Pipes. pp 148-154
B. A. Lawal, E. O. Arokoyo, S. O. Odeyemi
Keywords: Storm drain pipes, Erosion, catchment, discharge, rainfall pattern, chainages.
The Use of Geotechnical Investigation as a Tool for Detecting Seepage: A Case Study of Awba Dam University of Ibadan,Nigeria, pp155-163
O. A. Agbede and O. S. Oladejo
Keywords Awba dam, Anomalous seepage, fracture, geotechnical investigations, granular filter
A Study of Infectious Wastes from Medical Institutions in the Southwestern Nigeria: Treatment and Disposal Management, pp 164-175
S. O. Oladejo
Keywords Blood and blood products, hospitals, infectious wastes, medical institutions, sharps objects, recommendations
Dissolved Pure Water Sachet As a Modifier of Optimum Binder Content in Asphalt Mixes, pp176-184
Yinusa A. Jimoh and Stephen S. Kolo
Abstract : The Marshall properties of bitumen modified asphalt mix for wearing course of a flexible pavement were determined in the laboratory. The bitumen modification was achieved with dissolved pure water sachet in a petroleum bye product as a partial replacement of and additions to the optimum bitumen content. The variation of the Marshall Stability, flow and Voids in Mix (VIM), voids filled with binder (VFB) and voids in mineral aggregates (VMA) were monitored as the proportion of the emulsified dissolved sachets increased. The respective Marshall Stability values of 1,400 kg for unmodified bitumen binder; 1,150 kg at 15% partial replacement (1% dissolved pure water + 5 % optimum bitumen content = 6 % binder) and 1200 kg at 25 % addition (2% dissolved: pure water + 6 % optimum bitumen content = 8% binder) were recorded; which were both higher than the desired stability for heavily trafficked pavement. The dissolved pure water sachet modified asphalt through the two methods of application are equally effective to carry heavy traffic and still liberate the environment from the health hazards of the pure water waste sachets in rural and urban settlements. However, the modification method of additions to the optimum bitumen should be preferred because of its more consumption of the unwanted flying pure water sachet and save in quantity of bitumen in the production of asphaltic pavement mixes.
Key words: Dissolved pure water sachet, emulsion, optimum binder content, marshall stability, flow
Review of Theory of Visual Illusion and the Fact of the Sphere Shape, pp. 177-180
L Chows, Thomaz Liu and K Wenxia
Abstract: Illusions are fascinating to most people. Some of the illusions have been known since antiquity. The scientific study of illusions dates back to the beginning of the nineteenth century when scientists got interested in perception. Since then there has been enduring interest, and illusions have been used as tools in the study of perception. An important strategy in finding out how perception operates is to observe situations in which misperceptions occur. Theories about illusions have been formulated ever since their discovery. Some of the more famous theories on geometric optical illusions which can account for a number of illusions are: Ouchi Illusion, Wheels Illusion, Rotating Spiral, Moving sinusoids and Boogie Woogie illusion etc. When our visual system interprets the images received by our eyes, it carries out a large number of processes. The problem is how to analyze these processes as computations. Many of the computations are estimation processes. In other words quantities are estimated from the images (such as the location of edges and corners, the structure of the scene in view, or the position of the light source) using as input the image data, or the image data processed in some way. We are dealing with the errors-in-variable model in statistics using estimator, that is a procedure, to solve the equation system. The most common choice is by means of least squares (LS) estimation. However, it is well known, that LS estimation is biased. Under some simplifying assumptions (identical and independent random variables with zero mean and variance) the LS estimate converges. Therefore examples of visual computations which amount to linear equation systems are the estimation of image motion or optical flow, the estimation of the intersections of lines, and the estimation of shape from various cues, such as motion, stereo, texture, or patterns.
Keywords: least square estimator, visual illusion, sphere, pattern
Computer Aided Design for Maintenance Planning and Assessment for a Construction Company, pp 181-189
T K Ajiboye and W B Yusuf
Keywords: Computer Aided Design, periodicity, maintenance plans, complexities, maintenance frequency, preventive maintenance level, repair level.
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Model and Application for a Pothole in a Flexible Pavement Maintenance Due to Axle Loads, pp 1-7
Y. A. Jimoh
Key words Potholes, deterioration rate, cumulative traffic, standard axles and pavement maintenance stabilization
Neural Network Application in the Optimisation of Flood Control Structures, pp 8-20
M. Tohiib and S. O. Obidla
Abstract Neural network has been applied in the optimization of the flood control structure for a case study of dams in Ilorin in Nigeria Neural network search approach has been applied to optimize the design of these dams for controlling flood that plagues the Ilorin metropolis. The testing output parameters were compared with the expected values and found to fall within reasonable range although they were not exact values. The testing input data and the output data (both the expected and the network generated ones) by the neural network application have been presented
Keywords: Neural network, optimisation, structures, flood control
Interaction Analysis of a Structure’s Composite Action, pp 21-25
B Marszom and K.Mahmood
Abstract: No abstract
Energy Conservation through Site Optimization for Mobile Cellular Systems (Base Transceivers Station Optimization,, pp 26-33
Nasir Faruk, Mujahid Y. Muhammad, Olayiwola W. Bello, Abubakar Abdulkarim,Agbakoba John and Mohammed I. Gumel
Keywords: Base Transceivers Station (BTS), energy conservation, power consumption, access networkFullText__________________________________________________________________________________
Application of Artificial Neural Network for a Solar-Chimney System, pp 34-42
S. Q. Shiru and C McCannAbstract: Artificial Neural Networks are discussed as an alternative to linear regression for data modeling, prediction, forecasting and analysis in the social sciences This project entails the use of Artificial Neural Networks to optimize a solar chimney system in a residential building. Based on the analysis done using data obtained from model of an ideal solar chimney system of a residential building, the error difference between actual and expected results is minimal. This is due to flexibility of ANN to learn by example and is efficient at analyzing problems with incomplete data, and accurate prediction is sought more than expectation.
Keywords: Artificial, neural network, solar energy, chimney
Genetic Algorithm Based Design of Bearing Thrust Block for Horizontally Bent Ductile Iron Pipes, pp 43-50
A.R. Anwar, A.Y. Abdul Fatah, O.A.U. Uche, A.A. Adedeji
Abstract: The paper is aimed at optimizing bearing thrust block design for thrust restraint using Genetic Algorithm. The design was achieved by calculating the bearing Area from the design equation and then breaking the area in to the corresponding bearing width and height (b and h). The optimization was achieved by obtaining optimum values of the design variables (bearing width and height) that would give minimum volume of the truncated pyramid concrete block at the minimum bearing Area.Optimum values of the design variables obtained from genetic algorithm were successfully compared with the different values of the design variables obtained using the traditional Iterative approach. Five different iterates were compared with the Genetic Algorithm result for different soils. The volume was found to increase up to 95%, 90.97%, 74.55%, 59.72%, 33.77% and 119.05% for soft clay, silt, sandy silt, sand, sandy clay and hard clay respectively in contrast to Genetic Algorithm result. Optimum solution was found when the block height (h) varied between one and two times the block width (b) except for hard clay in which the block width was between one and two times the block height.
Keywords: Genetic algorithm, thrust Force, thrust block, optimization
FullText____________________________________________________________________________________Failure Detection in a Masonry Prism by Symlet Packet Analysis, pp 51-54
A. K. Aashuri
Abstract: In this study, an analytical method has been proposed for locating and quantifying the damage (crack) in a prismatic wall using wavelet packet analysis. The wavelet analysis has been carried out on the static deflection profile obtained by measuring deflection at a particular point while changing the locations of loads. The location of damage point is determined as the position of the peak in the curve of wavelet coefficient (WC) versus normalized length. The generalized curve/envelop of maximum WCs has been extracted to quantify the damage. The quantity of the damage was evaluated by mapping the modified wavelet coefficient (MWC) onto the generalized curve. Wavelet analysis has demonstrated its suitability for quantifying the damage (crack) in walls, beams and beam - like structures without a prior knowledge of the deflection corresponding to undamaged structure. Also this method can be extended to identify multiple damages in structural members of multiple spans. Hence, it can be adopted as a Structural Health Monitoring (SHM) tool for civil engineering infrastructures, most especially in bridge structures. So it can be recommended as an effective tool for preventive measure against excessive building failures and subsequent sudden collapse.
Keywords: Wavelet packet transforms deflection, parametric study, symlet.
A Pragmatic Approach to the Nigeria’s Engineering Infrastructure Dilemma, pp 55-61
O. G. Okeola and A.W. Salami
Key words: Infrastructure, service, deterioration, economy, failure
Different Plotting Position by Probability Analysis of Rainfall Data in Ilorin, Nigeria, pp 62-67
A. O. Ogunlela, A.S. Ahmed and S.C. Nwosu
Abstract: Plotting positions are useful in analyzing hydrologic variables such as rainfall, runoff, hydraulic conductivity and groundwater flow. Rainfall, a major component of the hydrologic cycle, is the most common form of precipitation in most parts of the world and its analysis with a probabilistic framework provides an important means of enhancing sustainable agricultural development of an area. This paper reports on the analysis of Ilorin rainfall data using different plotting positions. Ilorin, the study area, is located on Longitude 4 35' E, Latitude 8 30' N. It has two seasons: wet (March to October) and dry (November to February) and the heaviest rainfall occurs between June and September. Five different plotting positions were used to analyze the maximum monthly rainfall and annual rainfall data for Ilorin from 1989 to 2010: Weibull, Hazen, California, Gringorten and Cunnane. The return periods and the exceedance and cumulative probabilities were also computed. The Hazen, Gringorten and Cunnane plots were very close with Weibull fairly close to these three. California showed the greatest deviation for most parts of the plots.
Keywords: Plotting positions, probability, rainfall
Influence of Millet Husk Ash (Mha) on The Properties of Plain Concrete, pp 68-73
O. A. U. Uche, M. Adamu, and M. A. Bahuddeen
Abstract: This paper presents the result of an investigation on the likelihood of using millet husk ash (MHA) as a partial replacement of cement in concrete so as to reduce its high cost and find alternative disposal method for agricultural waste. The MHA was obtained by uncontrolled burning of millet husk at temperature of 400 – 600oc. Concrete mix proportion of 1:2:4 was used to produce cubes with varying MHA of 0, 5, 10, 15, 20, 30, 40 and 50 percent by weight of cement. A total of 192 cube specimens at 0.55 water cement ratio were tested for compressive strength at 3; 7; 28 and 56 days of age. The result shows that workability of fresh concrete decreases with increase in MHA content and this may not be unconnected with the water absorption capacity of MHA which has greater specific area than cement. Also linear shrinkage of MHA concrete increases with increase in percentage addition. The result of compressive strength increased at 5%MHA addition but decreases at higher percentage addition. At MHA increment up to 15%, the concrete compressive is still within the structural concrete grade of 20N/mm2. It is therefore recommended that at 0.55 water-cement ratio, that cement in structural concrete of 1:2:4 can be replaced with up to 15% MHA without impairing the compressive strength of the concrete and thus reducing cost.
Significance: The Use of MHA as pozzolana will not only contribute to the reduction of major environmental concerns raised by indiscriminate dubbing of waste but also reduce the cost of concrete production while improving the interfacial transition zone (ITZ) due to the pozzolanic reaction and the finer pore size distribution.
Keywords: MHA, pozzolana, concrete compressive strength, workability, and shrinkage properties.
Estimation of Aerosol in Building Design in a Tropical Sub-Region,pp 74-79
D. Mavundla and M. Pramod
Abstract: Case studies of administrative and residential building in the tropical sub-region, indicated that a substantial quantity of aerosols accumulates daily in the rooms of the buildings. The urban centre residential buildings have inadequate ventilation with a high pollution of an average flow rate of 5.33 and 2.11 ( x 103/s) were observed in public buildings and the agency of 1.18 and 2.12 ( x 10-6kg/s) respectively. The finite area method shows average of 10% aerosol accumulation on wall and furniture in residential buildings in the kitchens and 5% in the living rooms. 56% gas-based aerosols (smoke) are found in the traditional buildings (kitchens). The openings are, in most cases, adequate but poor rate of air flow, as a result of heat produced by the occupants and use of fire wood around the buildings, contributing immensely to sustenance of aerosols accumulated in the rooms. It has been recommended that additional ventilation (natural) be incorporated in the building design and that present buildings be ventilated using piping within the ceilings since most of the opening sizes are not adequate.
K eywords: Internal microclimate, aerosol, design, humid ,
A Structure and its Security against Blasts, pp80-83
K. Goell and B. Cypher
Abstract: Controlling the catastrophic collapse of a building by means of structural, architectural, and emergency envelope systems are among the best techniques to minimize blast effects. Terrorism has reached an advanced stage and the use the best materials available on the market within the reach of the terrorists' organizers. This work gives a brief means by which the governments and the designers have to be extra cautious while designing and testing blast containing buildings. In a terrorist attack. Most of the fatalities occur because of sudden collapse of any structures affected during an attack. The results show that 80 percent of the overall deaths were because of building collapse.
Keywords: Structure, blasts, collapse, security, terrorism
Propagation Path Loss Characteristics at 900 MHz in Ilorin, Nigeria, pp 84-93
P. R. Ogungbayi, A. J. Falade and Abubakar Abdulkarim
Abstract: One of the major parameters of interest in the analysis of radio wave propagation of mobile communication is the propagation path loss characteristics of an environment. This paper presents the determination of propagation path loss characteristic of power received at 900MHz in an urban terrain, Ilorin town, Nigeria. A Spectrum Analyzer was used to take measurements of signal strength from fixed transmitting antenna (base-station) at different distance using twelve different environments which reflect a good representation of Ilorin metropolis. The power received was analyzed to determine the propagation path loss exponent and path loss characteristics of the city investigated. The path loss exponent computed for Ilorin from this research is 2.60 which justify the low quality of GSM signal receive and sometimes network failure experience in the studied area. Suggestions and recommendations made on how to improve the quality of the GSM services in Ilorin metropolis.
Key words Path loss, path loss exponents, and quality of GSM services.
Evaluating Thermal Resistivity of Cement Plastered Straw Bale Wall:: A Review, pp 94-98
Abstract: In this work,,cement plastered straw bale specimens of sorghum and maize straw bale were tested for thermal conductivity using Lee’s disc apparatus. Thermal resistivity of the plastered straw bale specimens were evaluated as the reciprocal of the apparent thermal conductivity. The results of the experiment tests and calculations have shown that increase in the thickness of the plastered Straw bale masonry would increase their thermal resistivity. Though, this effect varies slightly from sorghum to maize Straw bale masonry, but at the thickness of 400 mm. The thermal resistivity of wood specimens measured with the same apparatus agreed to within 1.21 of the published values.
Keyword: Thermal resistivity, thermal conductivity, thermal resistance, sorghum, masonry
Software Development For Computing Evapotranspiration in Ilorin, Nigeria, pp 99-107
A. O. Ogunlela and S.O.Otukelu
Abstract: Evapotranspiration is a major component of the hydrologic cycle. Precipitation, surface runoff and underground seepage are other components of this cycle. Technology is used to determine the rate of evapotranspiration especially in fully developed societies. In developing nations like Nigeria, the awareness of the use of technology to compute evapotranspiration is not fully developed and as such several uninformed assumptions may be made. Several attempts have been made to relateevapotranspiration to meteorological data. All the methods are empirical or semi-empirical. In general, methods based on a single variable are unlikely to be generally applicable and combination methods at least attempt to model the whole effect of climate (although they are still semi-empirical and not fully theoretical). Each method generally works best in the region where it was developed and may require calibrating or be totally inapplicable to other regions. The impacts of temperature on evapotranspiration (ET) were assessed. Computation was based on the FAO Penman-Monteith equation. This equation accounts for the effects of air temperature changes on land-surface-atmosphere water vapour exchanges. Local calibration of this equation was done to determine ET rates for Ilorin and predict future effects.
Keywords: Climate change, evapotranspiration, penman-monteith equation
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Investigation of Dynamic Problems of Spherical Cavity in a Semi-infinite Solid, pp 108-121
T. K. Ajiboye and M. A. Abel
Keywords: Failure, stress, radius, shear angle, semi-infinite solid.
Short Note: Future Light Energy Emanating from Sound, pp 122-124
Abstract: This paper identified with a brief discussion on design, modeling validation of Future power generation that will use the same generator for the hydropower, but driven by a very low infrasound, ambient energy generator based on ambient vibrations to be used in remote and long term sensing networks. General submission and simulations studies validate the functionality of individual components in an integrated piezoelectric generator unit.
Keywords: Sound energy, light energy, hydroelectric generator, piezoelectric generator
Design Optimisation for Flood Control Structures by Neural Network, pp 124-138
S. O. Obidlah
Abstract: Neural network has been applied in the optimization of the flood control structure for a case study of dams in Ilorin. Neural network search approach has been applied to optimize the design of these dams for controlling flood that plagues the Ilorin. The testing output parameters were compared with the expected values and found to fall within reasonable range although they were not exact values. The testing input data and the output data (both the expected and the network generated ones) by the neural network application
Keywords: Neural network, optimisation, flood, structures
Vol. 2, No. 4, 2012
Assessing the Noise Pressure Level in Libraries’ Study Rooms in Nigeria – A Tropical Region, pp 139-151
H. T. Saka, A. S. Aremu, and A. A. Adedeji
Keywords: Environmental pollution, noise pressure level, library, study room
Solar Energy Application in Lighting Rooms – A Review, pp 152-157
Fousal Sanjay and A Thomas
Keywords: Rural development, lighting rooms, solar energy, solar PV, solar home system
Effect of Vertical Load and Water Table Fluctuation on the Bearing Thrust Block for Buried Pipes by Genetic Algorithm, pp 158-167
A.R. Anwar, A.Y. Abdul Fatah and A A Adedeji
Abstract: The study was aimed at studying effect of dead (weight soil overburden with underground water fluctuation) and surface live (dynamic truck load) loads on the design of bearing thrust block for buried pipelines under dynamic traffic loading using Genetic Algorithm. The design was achieved by calculating the bearing Area from the design equation and then breaking the area in to the corresponding bearing width and height (b and h).Three models were developed, the first one simulating dead and live loads, the second consisting the main design equation for bearing thrust block to provide the bearing area and the third model consists of the main design equation together with overburden soil weight (dead load) and truck loads (live load). Different heights of overburden together with different alternates of truck load were used for the simulation. It was found that the bearing area remains unchanged before and after the application of the dead and live loads. It was found that the effect of dead load due to the soil overburden pressure, fluctuation of water table and dynamic live load due to moving trucks did not affect the block soil interaction. It was concluded that the thrust force – soil equilibrium constraint is enough to give sufficient bearing area that would take care of the effect of the dead and live loads.
Keywords: Genetic algorithm, thrust block, dead and live loads, water table fluctuation
Determination of the Ultimate Bearing Capacity of Soils in Offa Community. pp 168-174
S. O. Odeyemi , M. B. Kaigama, A. O. Adeyemi and I. O. Amototo
Abstract: Beariing capacity is the intensity of loading that causes shear failure to occur beneath a foundation. This paper looks into t
he Ultimate Bearing Capacity of soils in Offa Community, a Metropolitan City in the Central part of Nigeria. Samples from Atari Area, Igosun Road Area, Amuyo Area, L.G.A, Lamodi Area and Ojoku Area in Offa were collected and tested. Tests such as soil moisture content, particle size analysis, Atterberg limit test, specific gravity test, Bulk density determination test and shear box test were carried out using the collected soil samples. These soils were analyzed and the results shows that the soil collected from the L.G.A area of type A-2-6 according to the AASHTO soil classification has the highest Ultimate Bearing Capacity for all the types of footings considered.
Keywords: Bearing Capacity, Soils, Settlement, Footings, Offa, AASHTO
PID Slip Control of Antilock Braking System incorporating Passive Suspension Dynamics, pp 175-183
Abstract: An Antilock Braking System (ABS) is an active safety device in road vehicles, which prevents the locking of wheels during emergency braking. Due to its non-linearity, it is expected that a PID controller will not perform optimally. In this work, a PID antilock braking system is developed, incorporating the passive suspension dynamics to further shorten the stopping distance due to the payload from the suspensions. The proposed system is tested on two road conditions; dry asphalt and dry gravel road conditions. Two external disturbances are introduced to demonstrate the impact of the suspension dynamics. The two external disturbances simulate a sinusoidal road profile and an inverse step function. The sinusoidal road scenario is frequently encountered on gravel roads and the inverse step function simulates a typical pothole situation. The results revealed that the proposed PID antilock brake system achieved shorter braking distance on a sinusoidal road profile compared to the inverse step scenario.
Keywords PID, ABS, slip control, friction model, passive suspension, road disturbance, ride comfort
Vol. 2, No. 5, 2012
Investigation of Building Thermal Insulation from Fan Palm Fiber, pp 184-192
Keywords Building, fan pan, fiber, thermal conductivity, density, materials
Recycled Waste Tyres as Geotechnical Engineering Materials: A Review, pp193-203
A. R. Anwar and Y. A. Abdulkareem
Abstract: Recycled waste employment in Geotechnical engineering projects attracts wide acceptability in recent years in environmental geotechnical engineering community. It offers benefit when viewed from standpoint of environmental protection, structural and economical point of view. Their low densities and high drainage property makes them attractive for use as lightweight materials on weak Subgrades and as retaining wall backfill. They are employed in different forms like bales, whole tyre, cut shred, chips, Buffing, granular and powder. This article is aimed at reviewing the previous works done on the use of scrap tyres in geotechnical engineering projects. Tyre stockpiles have been menace to our environment as they serve as hideout for vermin, rats and provides conducive atmosphere for mosquito breeding which spreads malaria that becomes responsible for the death of millions of people mostly children and pregnant women especially in developing world. The contribution of tyre stockpile to environmental degradation was thoroughly discussed in the paper. Some established properties of tyres of interest for engineering consumption were presented. And case histories where scrap tyres are used for Geotechnical engineering works with particular reference to road constructions in soft /expansive subgrades, embankment construction as well as retaining wall construction projects were introduced. Previous researches done on waste tyres for road constructions and retaining wall backfill providing information on the geotechnical characteristics and environmental impact of such applications were reviewed. It is found to be friendly to environment as it consumes the bulk of tyres that would have been detrimental to the environment and they do not have adverse effect on environment when employed in construction works. Cost analysis of the retaining walls backfilled with sand vs. shredded tyres as backfill materials to determine the economic benefit of using shredded tyres as the backfill material was also presented. The use of post consumer tyres was found to have economic benefits as it reduced the total cost of the project by 52% .63% and 67% for 3.048m (10ft) , 6.096m (20ft) and 9.144m (30ft) high retaining walls respectively.
Computation of Excess Air in Coal Fired Thermal Power Plant, pp 204-208
Keywords Excess air coefficient, formulas used, comparison
Drought Analysis for Ilorin, Nigeria, pp 209 -214
A. O. Ogunlela and E. F. Folowosele
Abstract: The occurrence of drought and its attendant effects on the environment, including agricultural programmes, have generated a lot of concern in Nigeria. This study was conducted in response to problems on drought damage and risk which could be reduced if adequate and precise drought forecasting mechanisms are put in place. Sixty six years of rainfall data (1946 – 2011) for Ilorin, were used in the analysis. Basic statistics were computed, including the mean, variance, coefficient of variation and skewness. The minimum daily rainfall ranged from 0.05 mm to 0.6 mm while the minimum monthly rainfall ranged from 0.25 mm to 76.8 mm. Four probability distributions were used: exponential, normal, log-normal and Extreme Value Type 1, including the Weibull plotting position. The extreme value distribution was the closest to the weibull (observed) plots for the daily and monthly events.
Vol. 3, No. 1, 2013
Reliability Design Format for Steel Plate Girder to BS 5950 (2000), pp 215-223
O. A. U. Uche and A. Ahmed
Abstract: The paper presents reliability assessment of deterministic design of steel plate girder considering both ultimate and serviceability limit state in accordance with BS 5950 (2000). The reliability analysis was carried out using First Order Reliability Method (FORM). Design variables such as strength of the material (Py), width of the flange, flange thickness, web thickness as well as the span of the girder were considered random and stochastic. It was shown among the findings that, when the span (L) of the plate girder was kept constant with increase in the magnitude of live-dead load ratio, the safety indices decreases, as deflection criterion was considered. Also, the design of the plate girder in accordance with BS 5950 considering shear and deflection is safe for almost all the range of variables considered. On varying the depth of the plate girder, safety indices increase with increase in depth and decrease with increase in live-dead load ratio, when shear criterion was considered. The deflection is the most critical mode of failure on varying the span and load ratio, with safety index less than the recommended value by JCSS 2000 for structural members with moderate to large consequences of failure of 3.3 to 4.4. Therefore, BS 5950 design result seems unsafe with respect to bending (under high live-dead load ratio) and satisfactory with respect to shear and deflection. It is then, recommended
that the design of steel plate girder base on BS 5950 be reviewed to incorporate reliability analysis.
Keywords Reliability design, steel plate girder, safety index, deterministic design
Comparative Study of Seismic Analysis for a Reinforced Concrete Bridge Column Reinforced with Steel and Shape Memory Alloy Wire, pp 224-232
S.O.Odeyemi and A.A. Adedeji
Abstract: SAP2000 Engineering software was utilized to investigate and compare the performance of a bridge column reinforced with steel and Shape Memory Alloy (SMA) wire subjected to earthquake ground excitations. A double span bridge of 10m span over Iyemoji River located in Ijebu-Ode (an area prone to seismic activities in Nigeria) was used in this study as a numerical example for analysis. Equivalent lateral force (Static) and time history method of seismic analysis were embarked upon to determine the deflection in the bridge column. It was observed from the static analysis that the introduction of SMA reduced the deflection in the column by 81.97%. The time history analysis using the Elcentro earthquake ground excitation also revealed that the maximum deflection of the column was reduced by 43.66%. From the results of both the static and time history analysis, the deflection of the column was reduced by an average of 62.81% with the introduction of SMA.
Keywords Shape memory alloy, bridges, earthquake, static analysis, time history analysis, SAP2000
Scaled Based Reinforced Concrete Framed in Smart Structural Materials on Spectral Ordinate, pp 233-251
Abstract: The seismic behaviors of bare three storey concrete frame and with the application of Macro Fiber Composite (MFC) Shape Memory Alloyed (SMA) have being assessed and compared in this study. Modeled concrete frames are designed and analyzed according to recent seismic design standard (USB), using both static and dynamic analyses to know the maximum storey drift corresponding to each of this frames. The accepted Elcentro earthquake ground motion record was employed to simulate the models for dynamic analysis. The accelerogram that was chosen for analyzing the designed reinforced concrete frames was scaled based on the spectral ordinate at the fundamental periods of the frames. The behaviors of the three modeled frames, under scaled seismic excitation are compared. In terms of maximum inter storey drift and residual top storey drift. The results show that SMA yields a better performance than MFC, in reducing the maximum storey drift of the frame even after a strong earthquake.
Keyword Smart structure, macro fibre component, shape memory alloy, reinforced concrete, frame
Introducing the Use of Evolutionary Programming by Applying ChaosTheory (II), pp 252-260
Abstract: A single cell would struggle hard, among a pool of cells, to survive, while another cell would also struggle harder and another very hard, but who ever is fit among the population of cells would survive. Survival in this sense does not mean that the harder the fitness, rather the survival is fit by random selection or chaos and not by order. The random chance of variation together with the law of selection is a problem-solving method of immerse power. This work introduces the use of this principle to optimize design of scientific and engineering problems. Basic binary/decimal conversion i.e, conversion to and from other numeral systems were enumerated to ease a programme.
Keywords: Chaos theorem, genetic algorithms, genetic programming, evolutionary programming
Environmental Impact of Road Dualisation: A Case Study of Mokola-Ojoo Road in Ibadan, pp 264-266
W.O. Ajagbe, A.A. Ganiyu and S.A. Bashiru
Abstract: The impacts of the dualisation of Mokola - Ojoo road in Ibadan, Nigeria on the inhabitants, socio-economic activities, biological and air environment were studied using physical observation and questionnaire survey. The dualisation caused the demolition of some adjoining structures and historic site, displacement of the inhabitants, the pollution of air with dust and carbon monoxide and brought untold hardships on the road users. Although the long term benefit of the dualisation is well recognized, the negative impacts may as well reduce the benefit thus establishing the importance of conducting proper Environmental Impact Assessment prior to the commencement of the project.
Keywords Environmental impact assessment, road dualisation, traffic.
A Study of Effects of Different Particle Sizes on some Densification Characteristics of Corncob Briquettes, pp 267-271
Abstract: Corncob is one of many agricultural residues being generated in Nigeria and whose potentials are yet to be fully tapped for energy generation. The study was undertaken to investigate the effects of particle sizes on the properties of fuel briquettes produced from three particle sizes. Corncob residues were obtained from a processing mill, sun-dried for three days and were reduced by a combination of choppers and milling machines. They were sieved into three particle sizes 4.70, 2.40 and 0.60mm representing coarse, medium and fine series respectively. A briquetting machine was used for manufacturing of briquettes at a pressure of 4.40 MPa. Starch mutillage of 25% by weight of the residue was added as binder. A dwell time of 120 seconds was observed for the briquettes during formation. The initial, maximum and the relaxed densities of the briquettes were determined. The compaction, density as well as relaxation ratios were also determined. The briquette dimensions were measured and through this the briquettes stability was determined. The sample contained 30.35% of particle size 4.70mm (S1), 20.10% of particle size 2.40mm (S2) and 13.8% of particle size 0.60mm (S3). The mean bulk density of the unprocessed corncob residue was 50.32 kg/m3, while the relaxed densities for particle S1, S2 and S3 were 337, 365 and 420 kg/m3 respectively with the finest particle having the highest. This translates to percentage volume reduction of about 670, 725 and 835 % for particle S1, S2 and S3 respectively. The maximum densities for the particle size S1, S2 and S3 varied from 802 to 646 kg/m3. The study concluded that the finer the particle size, the lower the maximum density, and the higher the relaxed density.
Key words Binder ratio, briquettes, compaction pressure, particle size
Vol. 3, No. 2, 2013
Quality Assessment of Sandcrete Blocks in Ibadan – A review, pp 272-277
W.O. Ajagbe, A.A. Ganiyu and A.A. Adeniji
Abstract: Sandcrete blocks have been widely used for modern building construction in Nigeria; however cases of incessant building collapse are rampant. The usage of substandard sandcrete blocks is a contributing factor. This research was carried out to assess the engineering properties of sandcrete blocks produced in Ibadan and its environs. Two blocks each of size 450 x 225 x 225mm were purchased from selected block industries at eight sampled locations within the study area. Few units of blocks (450 x 225 x 225mm) conforming to the Nigerian Industrial Standard (NIS 87:2007) were also produced to serve as control samples. The 28th day dry compressive strength test result obtained for the sampled blocks ranges between 0.39-2.34N/mm2. For the control block samples, the average 28th day dry compressive strength of the three tested blocks was 3.02N/mm2. Conclusively, it was observed that the sandcrete blocks produced in major parts of Ibadan were of low quality and substandard; while the control samples were of adequate strength.
Keywords Sandcrete blocks, compressive strength, Ibadan
Use of Sherman’s Equation and Rational Methods to Develop Discharge Runoff during Excessive Flooding, pp 278-288
M. Hammed and Z.Adeola
Abstract: The Sherman’s equation and rational method were used to develop discharge runoff for the area of study. The peak runoff discharge was carried out, using the rainfall intensity-frequency-duration on the rainfall data collected for the study area and rational method. It was observed that the lower the time of duration the higher the peak runoff discharge and rainfall intensity. The study area, Ikorodu, was visited where drainage systems and buildings were observed. Improper dumping of refuse into the river channel which eventually blocks water ways making the water to find alternative routes; poor soil infiltration rates, as a result of impermeable rocks in the areas, aggravate flood which affected the buildings; and poor drainage system that disallowed the flow of water to pass through the appropriate channels and culverts. Use of water resistant cement is recommended for plastering of buildings up to the design flood level of 0.2m above sea level for Lagos metropolis.
Keywords: Sherman’s Equation, flood, rational method, runof
Dynamic Analysis of a Multistory 2D Truss Structure Subjected to Seismic Loadings, pp 289-305
V. S. Kamara and D. Katale
Abstract: This finding deals with performance based design assessment of two dimensional multistory plane truss (braced frame) structure subjected to arbitrary ground motions (earthquake records) and load conditions. For numerical analysis technique, Finite Element method has been used. A MATLAB code was developed for the static and dynamic response of the multistory plane truss structure. The frequencies and mode shapes of the structure when subjected to varying earthquake loads has been determined and graphically presented in order to verify the numerical analysis experimentally. The Performance Based Design (PBD) philosophy is adopted mainly for the assessment of low and high rise reinforced concrete truss buildings. Seismic standards have been developed to guide the buildings in such a way that they do not collapse when subjected to specified design earthquakes. There are five earthquake records that were used to determine various response quantities of the building. The structure was subjected to the five different earthquake records using time stepping procedure called the Central difference Method (algorithm) and this algorithm was coded in MATLAB for the analysis with a smaller time step. This is done because an adequate response of a structure cannot be predicted with only one earthquake record and moreover, these records are previous record from previous earthquake.
Keywords: Finite Element method, dynamic response, mode shapes, earthquake, MATLAB
A A. Adedeji and M. A. Olaosebikan
Abstract: Objective of this finding involved the review of bond strength between reinforcing steel rods coated with bitumen for mild and high tensile steels and concrete in which the rods were embedded; and investigating compressive strength of the reinforced concrete, relative to their bond strength. High tensile reinforcement was coated with bitumen and sand whenever the materials are to be employed for use in reinforced concrete works. It has been shown that the bond strength of each of the conditioned reinforcing bars increased with compressive strength of the normal concrete with increase in curing age. The general pattern of behaviour of bond strength of the two types of reinforcement rods used under different surface conditions, indicating increase in their bond strength at the curing age of 28 days. The bond failure in round plain reinforcement bars were accompanied with cracks. Such failure was associated with pronounced vertical crack in high tensile steel bars. The finding confirmed mild steel reinforcement is should mot coated with bitumen at all when employing it for use in a construction works.
Keywords Bond strength, bitumen, steel reinforcement, concrete
Application of Neural Network in the Optimal Design of Flood Control Structures, pp 317-329
M. Tohiib and S. M. Najiib
Abstract: Neural network has been applied in the optimization of the flood control structure in Selangor. Neural network search approach has been applied to optimize the design of these dams for controlling flood that plagues the Selangor. The testing output parameters were compared with the expected values and found to fall within reasonable range although they were not exact values. The testing input data and the output data (both the expected and the network generated ones) by the neural network application have been presented.
Keywords: Neural network, optimisation, structures
Vol. 4, No. 1, 2014 Reliability Design Format for Steel Plate Girder to BS 5950 (2000), pp 330-338 O. A. Ahmed and O. A. Uche Abstract: The paper presents reliability assessment of deterministic design of steel plate girder considering both ultimate and serviceability limit state in accordance with BS 5950 (2000). The reliability analysis was carried out using First Order Reliability Method (FORM). Design variables such as strength of the material (Py), width of the flange, flange thickness, web thickness as well as the span of the girder were considered random and stochastic. It was shown among the findings that, when the span (L) of the plate girder was kept constant with increase in the magnitude of live-dead load ratio, the safety indices decreases, as deflection criterion was considered. Also, the design of the plate girder in accordance with BS 5950 considering shear and deflection is safe for almost all the range of variables considered. On varying the depth of the plate girder, safety indices increase with increase in depth and decrease with increase in live-dead load ratio, when shear criterion was considered. The deflection is the most critical mode of failure on varying the span and load ratio, with safety index less than the recommended value by JCSS 2000 for structural members with moderate to large consequences of failure of 3.3 to 4.4. Therefore, BS 5950 design result seems unsafe with respect to bending (under high live-dead load ratio) and satisfactory with respect to shear and deflection. It is then, recommended that the design of steel plate girder base on BS 5950 be reviewed to incorporate reliability analysis. Keywords Reliability design, steel plate girder, safety index, deterministic design An Empirical Assessment of Causes of Building Collapse in Lagos State, Nigeria, pp 344-352 O. G. Okeola A. A. Okeola and M. G. Ameen Abstract:
The unremitting cases of building collapses in Nigeria have become a
source of national and international concern. Many efforts have been
directed towards identifying the critical factors responsible for these
collapses with the aim of finding appropriate strategies that is
proactive and pragmatic in preventing further occurrences. One of the
bottlenecks that have clog efforts to determine the causes of collapses
is the absence of a comprehensive analysis of records of building
collapses. This study gives an empirical assessment of causes of
building collapse in an economic hub state of Nigeria by statistically
analysing records of building collapses in Lagos state. The findings
indicate poor quality materials and workmanship, faulty
design/construction methodology and excessive loading as the major
factors responsible for building collapses in Lagos state. Based on the
findings recommendations to stem the tide in the short and long term
were given. Keywords: Building Collapse, Structural, workmanship, materials, Lagos
Vol. 4, No. 1, 2014
Reliability Design Format for Steel Plate Girder to BS 5950 (2000), pp 330-338
O. A. Ahmed and O. A. Uche
Abstract: The paper presents reliability assessment of deterministic design of steel plate girder considering both ultimate and serviceability limit state in accordance with BS 5950 (2000). The reliability analysis was carried out using First Order Reliability Method (FORM). Design variables such as strength of the material (Py), width of the flange, flange thickness, web thickness as well as the span of the girder were considered random and stochastic. It was shown among the findings that, when the span (L) of the plate girder was kept constant with increase in the magnitude of live-dead load ratio, the safety indices decreases, as deflection criterion was considered. Also, the design of the plate girder in accordance with BS 5950 considering shear and deflection is safe for almost all the range of variables considered. On varying the depth of the plate girder, safety indices increase with increase in depth and decrease with increase in live-dead load ratio, when shear criterion was considered. The deflection is the most critical mode of failure on varying the span and load ratio, with safety index less than the recommended value by JCSS 2000 for structural members with moderate to large consequences of failure of 3.3 to 4.4. Therefore, BS 5950 design result seems unsafe with respect to bending (under high live-dead load ratio) and satisfactory with respect to shear and deflection. It is then, recommended that the design of steel plate girder base on BS 5950 be reviewed to incorporate reliability analysis.
Keywords Reliability design, steel plate girder, safety index, deterministic design
An Empirical Assessment of Causes of Building Collapse in Lagos State, Nigeria, pp 344-352
O. G. Okeola A. A. Okeola and M. G. Ameen
Abstract: The unremitting cases of building collapses in Nigeria have become a source of national and international concern. Many efforts have been directed towards identifying the critical factors responsible for these collapses with the aim of finding appropriate strategies that is proactive and pragmatic in preventing further occurrences. One of the bottlenecks that have clog efforts to determine the causes of collapses is the absence of a comprehensive analysis of records of building collapses. This study gives an empirical assessment of causes of building collapse in an economic hub state of Nigeria by statistically analysing records of building collapses in Lagos state. The findings indicate poor quality materials and workmanship, faulty design/construction methodology and excessive loading as the major factors responsible for building collapses in Lagos state. Based on the findings recommendations to stem the tide in the short and long term were given.
Keywords: Building Collapse, Structural, workmanship, materials, Lagos